lstat_cache(): introduce invalidate_lstat_cache() function

In some cases it could maybe be necessary to say to the cache that
"Hey, I deleted/changed the type of this pathname and if you currently
have it inside your cache, you should deleted it".

This patch introduce a function which support this.

Signed-off-by: Kjetil Barvik <barvik@broadpark.no>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/cache.h b/cache.h
index 7c8c8e4..f4452a8 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -722,6 +722,7 @@ extern int checkout_entry(struct cache_entry *ce, const struct checkout *state,
 extern int has_symlink_leading_path(int len, const char *name);
 extern int has_symlink_or_noent_leading_path(int len, const char *name);
 extern int has_dirs_only_path(int len, const char *name, int prefix_len);
+extern void invalidate_lstat_cache(int len, const char *name);
 
 extern struct alternate_object_database {
        struct alternate_object_database *next;

diff --git a/symlinks.c b/symlinks.c
index 918e24a..31ddbc9 100644 (file)
--- a/symlinks.c
+++ b/symlinks.c
@@ -12,23 +12,30 @@ static struct cache_def {
  * Returns the length (on a path component basis) of the longest
  * common prefix match of 'name' and the cached path string.
  */
-static inline int longest_match_lstat_cache(int len, const char *name)
+static inline int longest_match_lstat_cache(int len, const char *name,
+                                           int *previous_slash)
 {
-       int max_len, match_len = 0, i = 0;
+       int max_len, match_len = 0, match_len_prev = 0, i = 0;
 
        max_len = len < cache.len ? len : cache.len;
        while (i < max_len && name[i] == cache.path[i]) {
-               if (name[i] == '/')
+               if (name[i] == '/') {
+                       match_len_prev = match_len;
                        match_len = i;
+               }
                i++;
        }
        /* Is the cached path string a substring of 'name'? */
-       if (i == cache.len && cache.len < len && name[cache.len] == '/')
+       if (i == cache.len && cache.len < len && name[cache.len] == '/') {
+               match_len_prev = match_len;
                match_len = cache.len;
        /* Is 'name' a substring of the cached path string? */
-       else if ((i == len && len < cache.len && cache.path[len] == '/') ||
-                (i == len && len == cache.len))
+       } else if ((i == len && len < cache.len && cache.path[len] == '/') ||
+                  (i == len && len == cache.len)) {
+               match_len_prev = match_len;
                match_len = len;
+       }
+       *previous_slash = match_len_prev;
        return match_len;
 }
 
@@ -63,7 +70,7 @@ static inline void reset_lstat_cache(int track_flags, int prefix_len_stat_func)
 static int lstat_cache(int len, const char *name,
                       int track_flags, int prefix_len_stat_func)
 {
-       int match_len, last_slash, last_slash_dir;
+       int match_len, last_slash, last_slash_dir, previous_slash;
        int match_flags, ret_flags, save_flags, max_len, ret;
        struct stat st;
 
@@ -81,7 +88,8 @@ static int lstat_cache(int len, const char *name,
                 * Check to see if we have a match from the cache for
                 * the 2 "excluding" path types.
                 */
-               match_len = last_slash = longest_match_lstat_cache(len, name);
+               match_len = last_slash =
+                       longest_match_lstat_cache(len, name, &previous_slash);
                match_flags = cache.flags & track_flags & (FL_NOENT|FL_SYMLINK);
                if (match_flags && match_len == cache.len)
                        return match_flags;
@@ -167,6 +175,26 @@ static int lstat_cache(int len, const char *name,
        return ret_flags;
 }
 
+/*
+ * Invalidate the given 'name' from the cache, if 'name' matches
+ * completely with the cache.
+ */
+void invalidate_lstat_cache(int len, const char *name)
+{
+       int match_len, previous_slash;
+
+       match_len = longest_match_lstat_cache(len, name, &previous_slash);
+       if (len == match_len) {
+               if ((cache.track_flags & FL_DIR) && previous_slash > 0) {
+                       cache.path[previous_slash] = '\0';
+                       cache.len = previous_slash;
+                       cache.flags = FL_DIR;
+               } else
+                       reset_lstat_cache(cache.track_flags,
+                                         cache.prefix_len_stat_func);
+       }
+}
+
 #define USE_ONLY_LSTAT  0
 
 /*